[Mike C]

Because of how the cross members are positioned on the 2x4 vs 4x4 trucks and how the engine is further forward on the 2x4 trucks and then the trans linkage, it's much easier to tuck the 4 wheel drive header. On my Jimmy the Heddmans that are/were on it appear to be the same as Special K's. They appear to be the same as the 63-82 Corvette and have a #1 cylinder pipe that is at a steeper angle than the Chevelle headers and shorter overall height to work with the rearward engine position.

That's why the 2x4 exhaust hangs lower than the 4x4 and why the solution has been to go to car headers and the 2nd gen Camaro and Chevelle headers appear to be the best fit.